Lock.



PATENTED DEC. 11, 1906.

I. W. SCHROEDER.

LOCK. APPLICATION FILED APB.13,1906.

WITNESSES FREDERICK WV. SCHROEDER, OF LONDON, ENGLAND.

LOCK.

Specification of Letters Patent.

Patented Dec. 11, 1906.

Application filed April 13,1905. Serial No. 255.401-

To (all whom, it may concern:

Be it known that I, FREDERICK WVILLIAM Sorrnonnnn, engineer, a subject of the King of Great Britain, residing at 9 Ai'undel street, Strand, London, England, have invented certain new and useful Improvements in and Relating to Locks, of which the following is a specification. Y

This invention relates to locks of the kind which are commonly known as cylinderlocks and to keys for operating the same.

According to the present invention the serrated edge of such keys are provided with a protective flap whereby the working parts are protected from attrition when not in use, and, further, it is rendered impossible or difficult to obtain an impression or model of the working parts of the key for purposes of fraud or otherwise.

The invention further involves a simplification of such locks by the reduction of the number of working parts thereof.

The improved lock and key are illustrated in the accompanying drawings, in which Figure 1 is a longitudinal section with parts broken away; and Fig. 2, a transverse section on line 2 2, showing the key fitted in the lock and the tumblers withdrawn to enable the barrel to be rotated by the key. Fig. 3 is a side and end elevation of the key; Fig. 4, a transverse section similar to Fig. 2, but showing the tumblers retracted too far by the insertion of an improper key. Fig. 5 is a crosssectional view on the line 5 5 of Fig. 1.

Mounted to slide transversely in the lock barrel or plug a, which is provided with a suitable longitudinal ward or wards for the reception of the key 5 by which it is rotated are tumblers c, which cooperate each with a corresponding serration b of the key-bit. These tumblers are urged in one irection by means of springs d, which are compressed between the heads c of the tumblers and collars or projections d in the interior of the lock-barrel to engage in a slot or in holes e in a fixed inner casing or sleeve 6, surrounding the barrel a and secured to the outer lockcasing is, and are urged in the opposite direction by their hook-shaped lower ends 0 encountering the serrations b of the key-bit as vthel g i erisinsnfts t fhenentrallrepvay. ThetiTmblers arepreferably bifurcated or U-shaped, one of the limbs of the fork namely, the pin part 0 already described being arranged to slide in a transverse recess in the lock-barrel a, while the other limb f of the fork slides in another transverse hole or slot or in a transverse slit 9 in the outer surface of the barrel. The tails f of the limbs f cooperate with a slot or holes f in the fixed sleeve e, the arrangement being such that when the key of a given'lock has been properly inserted therein the bifurcated tumblers are pressed, and the springs d, pressing against the heads 0, hold the hooks c in engagement with the corresponding rentrant serrations of the key I), the heads 0 and the tails f of the bifurcated tumblers being then flush with, or at any rate not projecting beyond, the surface of the barrel a, so that the latter may be turned by means of the key and the lock-bolt thereby retracted. When any key differing materially from the proper key is inserted in the keyway, then one or more of the heads or tails or both of the bifurcated tumblers will project into the slots or holes 6 f and prevent the rotation of the barrel and the retraction of the lock-bolt.

The protecting flap or hood 6 of the key may be formed in one piece with the key or may be separately formed and afterward attached to it, the edge of the flap bein arranged to overlap the serrated edge 0 the key-bit, forming a guard or shield therefor, as shown in Fig. 2.

It may be convenient in order to increase the possible range of movement of the tumblers to make a slot or groove or holes h in the protective flap 5 so as to allow the lower ends of the tumblers c to project into or through such grooves or holes as the key is pushed home into its position in the lock, such grooves, slots, or holes corresponding in position with the points of the teeth or of one or more of the serrations of the key.

I claim 1. The combination with a lock-casing, of a lock barrel or, plug having a ward projecting into a central keyway in said plug and spring -pressed tumblers movable transversely in holes in said ward, said tumblers having lugs projecting laterally into said central keyway; substantially as described.

2. The combination with a lock-casing provided with a series of recesses, of a lock barrel or plug having a ward projecting into a central keyway in said plug, and springpressed tumblers movable transversely in holes in said ward, adapted to enter said recesses to lock the plug to the casing said tumblers having lugs projecting laterally into said central keyway; substantially as described.

3. The combination with a lockcasing having a plug provided with a keyway, and tumblers movable in holes in the plug and provided with-lugs projecting laterally into the keyway, of a bitted key to engage the lugs and provided with a protecting-hood for the bitted portion, the keyway being shaped to receive the hood.

4. The combination with a lock-casing, of a lock barrel or plug, having a ward projecting into a central keyway in said plug, tumblers movable in holes in the ward, said tumblers and said ward having lugs projecting laterally into said keyway, and a key having a protected bitted edge for engaging the lugs on the tumblers; substantially as described.

5. The combination with a lockcasing provided with a series of recesses, a lock barrel or plug having a central keyway, awardprojecting into said keyway and springpressed tumblers adapted to enter said recesses, of a key having a protected bitted edge constructed to retract the tumblers from the casing; substantially as described. 6. The combination with a lock-casing provided with a series of recesses, a lock barrel or plug having a central keyway, a ward projecting into said keyway and springpressed tumblers having lugs adapted to enter said recesses, of a key having a protected bitted edge constructed to engage said lugs to withdraw the tumblers from the casing; sub-.

stantially as described.

7. In a tumbler-lock, the combination of a casing provided with a series of recesses, a barrel or plug within the casing having a central keyway and a longitudinal ward projecting into said keyway, there being channels leading through said ward into said keyway, I

and bifurcated spring-pressed tumblers each having one limb or stem operating in a channel and the other limb in a slot in the outer surface of the plug; substantially as described.

8. In a tumbler-lock, the combination with a casing provided with a series of recesses, a barrel or plug within the casing having a central keyway and a longitudinal ward projecting into said keyway, there being channels leading through said ward into said keyway, bifurcated spring-pressed tumblers each having one limb or stem operating in a channel and the other limb in a slot in the outer surface of the plug, of a key having a ing shanks or stems provided with projecting.

lugs, of a key having bittings or serrations for engaging said lugs and provided with a protecting hood or guard for the bittings; substantially as described.

10. In a tumbler-lock, the combination with a casing provided with a series of recesses, of a plug within the casing provided with a keyway and having exterior and inte rior channels, and bifurcated tumblers adapted to move in said channels and to enter said recesses; substantially as descrlbed.

11. In a tumbler-lock, a casing provided with a series of recesses, a plug within the casing provided with a keyway and a ward projecting into said keyway said plug having exterior and interior channels and bifurcated tumblers adapted to move in said channels and to enter said recesses; substantially as described.

12. The combination with a lock-casing, of a barrel or plug, having a U-shaped keyway and a longitudinal Ward, spring-pressed tumblers projecting into the keyway the casing being provided with a separate series of recesses opposite the respective ends of the tumblers, and a key having a bitted edge and a protecting-hood therefor adapted to pass on opposite sides of said ward and engage the tumblers; substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

FREDERICK W. SCHROEDER.

Witnesses:

JosEPH MILLARD, WALTER J SKERTEN. 

